Recently, in the semiconductor device in which multiple elements are driven in parallel, a silicon carbide, which is one of semiconductors called as wide band-gap semiconductor, has been employed as a material of a part of the elements. For example, an SiC switching element including SiC as a main constituent has low on-resistance compared to an Si switching element including silicon as a main constituent and can reduce power loss. Also, since the SIC switching element can be operated under high temperature condition compared to the Si switching element, it has been expected to miniaturize a cooling mechanism for the SiC switching element.
A power semiconductor module described in the patent literature 1 includes an inverter in which an insulated gate bipolar transistor (i.e., IGBT) and a free-wheeling diode (i.e., FWD) are connected in parallel. In the above power semiconductor module, the FWD is formed of SiC to reduce recovery loss and switching loss, and thereby to reduce a quantity of heat generated in the FWD. As a result, in addition to characteristics of SiC that can be employed in high temperature region, allowable operating temperature of the FWD is expanded, and miniaturization of the power semiconductor module is achieved by decreasing the performance of the cooling mechanism.